Mine clearing device



Dec. 17, 1963 L. R. LITTLETON MINE CLEARING DEVICE Filed April 29, 19531 I 2 I a INVENTOR. Leonidas R. Lifl'letcn-L f Y H 'lTaRMsYs.

United State ate; I fiice 3,114,316 Patented Dec. 17, 1963 3,114,316MINE CLEARING DEVICE Leonidas R. Littleton, Arlington, Va., asslgnor tthe United States of America as represented by the Secretary of the ArmyFiled Apr. 29, 1953, Ser. No. 352,066 1 Claim. (Cl. 102-22) (Grantedunder Titie 35, US. Code (1952), see. 266) The invention describedherein may be manufactured and used by or for the Government forgovernmental purposes without the payment to me of any royalty thereon.

The present invention relates to a detonating cable or line charge.

Various methods and devices have been proposed for clearing mine fields,for cutting pathways through dense forests and underbrush. Among some ofthe mechanical devices used for these purposes may be numbered, bombs,snakes, hose filled with liquid explosives, explosive sprays, projectedline charges etc.

So also in ground warfare it is frequently desirable to have available adevice that can quickly and easily be laid out in any desired pattern tofunction as an anti-personnel weapon. To this end it is necessary thatthe assembly be light, easily, and safely handled, and positive inaction so that a very flexible and versatile ordnance mechanism isproduced.

Detonating cables and line charges in present use generally include aplastic explosive charge which is first wrapped around a nylon rope,then encased in a pliable plastic envelope, and the whole than coveredwith a plurality of nylon sleeves. This device is then tied tightly atregular distances to simulate a sausage shape, wherefore the explosiveis separated into short segments to make the cable flexible.

The aforementioned nylon sleeves are not only expensive but diflicult toprocure. Additionally the method of loading, assembling and tying thedevices is laborious, tedious and consequently excessively expensive.

It is accordingly a primary object of this invention to provide adetonator cable in which the materials and elements are relatively cheapand readily available, and can easily be assembled to provide aninexpensive device.

Another object of this invention is to provide a flexible detonatorcable in which solid cylindrical blocks of preformed explosives arestrung along a flexible rope to produce an ordnance weapon which iseasily handled, easily shipped, stored and used, and inexpensive.

A further object is to provide a detonator cable for clearing minefields, underbrush, wooded areas, and for anti-personnel use, in whichthe separate explosive blocks are capable of assembly to produce aninexpensive line charge of greater flexibility to facilitate handlingand storing.

A still further object of this invention is to provide a noveldetonating cable, having the foregoing recited characteristics, whichwill be positive in action and of decreased risk in handling.

Other features and advantages of the invention will become apparent froma consideration of the following specification, and of the drawingwherein FIGURE 1 is a view in elevation of the device of the instantinvention wherein several of the explosive blocks are shown joinedtogether to form a flexible cable.

FIGURE 2 is a longiuditnal section through one of the explosive blocksof FIGURE 1.

FIGURE 3 is a transverse section on line 33 of FIG- URE 2 and,

FIGURE 4 is a modification according to FIGURE 2 to illustrate analternate method for joining the explosive blocks together.

Referring more particularly to the drawing wherein like referencecharacters designate like or corresponding parts through the severalviews, 1 designates a series of rigid, cylindrical blocks of explosive,each preformed to have at least one rounded end 2 to prevent fouling ofthe device and to decrease resistance while being projected over land orwater, and having axial bores 3 whereby the blocks may be strung inequally spaced relation upon a flexible, elongated rope or cable 4, ofsuitable material such as nylon, sisal, hemp or any other kind of rope,which may or may not be reinforced by metal as desired.

One or more radially displaced, longitudinal bores 5, parallel to and inclose proximity to axial bore 3 are also preformed in each block toreceive a Primacord 6 to insure a continuously progressing detonatingchain for each successive explosive block, in the event the spacedrelation between adjacent blocks is too great to transmit detonation.

The Primacord 6 is preferably looped between adjacent blocks, as at 7 toaid in providing a flexible cable and to prevent strain and breakage ofthe Primacord when the line charge is under tension. If desired, ahelical reinforcing wire 8 as shown in FIGURE 4 may be providedcoextensive with loop 7 on the Primacord to insure retention of theloop.

In the species illustrated in FIGURE 4, instead of longitudinal bores 3and 5, each end of each block 1 is provided with preformed centralcavities 3 of the same diameter as bores 3, and preformed radiallydisplaced cavities 5', equal in diameter to bores 5. Cavities 3' areprovided to receive the ends of shorter pieces of flexible rope 4, whichare rigidly secured to the blocks in any convenient manner. In likemanner cavities 5 are provided to receive looped sections 7 of Primacord6 which again are secured to the blocks 1 to provide a rigid connection,but in a manner to insure sutficient contact between each Primacord endand its respective block. A suggested, though not necessarily preferredor limiting method for insuring rigid connections between blocks 1, rope4 and Frimacord 6, is to provide cavities 3 and 5' respectively withpress fitted internally threaded plastic sleeves or sockets 9, 9' andthe ends of nylon rope 4 and Primacord 6, with externally threadedsleeves 4' and 6' respectively. In this manner the preformed blocks 1,ends of rope 4, and looped ends of Primacord 6 may be boxed and shippedseparately and assembled prior to use. With this modification the lengthof each line charge may be limited to depend on its particular use.Additionally the savings are greater due to the need to provide muchshorter lengths of expensive nylon rope 4, and Primacord 6 for eachrespective detonator cable length.

In making the explosive block forming a part of this invention, theexplosive may either be extruded or pressed with a binder, or moldedwith a thermosetting plastic, proper means also being included topreform the flexible rope and Primacord bores or cavities, and therounded block end. Examples of the type of explosive utilized to formthe blocks are the Well known explosives commonly designated as RDX,PETN, or compositions containing a proper mixture of both. Any suitablebinder such as a resin or wax may be used, which will combine with theexplosive to form a rigid mass. Any suitable thermosetting plastic witha proper accelerator which does not react with the explosive may also beused to preform the block. It is proposed to make each explosive blockof a length such that the assembled device may be conveniently foldedinto a shipping or dispensing pallet, with the finished articlecontaining from 2 to 8 pounds of explosive per linear foot of cable.

It can readily be seen, therefore, that the above description disclosesa flexible detonating cable or line charge, which is made of explosiveblocks that are rigid and may Q be stored, shipped, and handled withease and facility, and without the need for the usually providedexpensive inner envelope and outer sleeves. The cable is flexible andcan be quickly laid out in any desired length orpattern by a minimum ofpersonnel. It can be fired or set 'off by a trip wire, step onattachments, or by remote control by an operator. It can be buried, laidon the ground, hung 'in trees or on poles, along road sides, in minefields,

planted on beaches, or hedgerows and in any pattern depending on itsintended use. For anti-personnel work the weapon may be made moreeffective by encircling each explosive block with fracturable metalrings.

Thus a simple, flexible, compact, reliable, inexpensive and easilyhandled detonating cable has been described. Other modifications andalterations to the structure disclosed will be apparent to one skilledin the art, and it is obvious that the same may be made withoutdeparting from the spirit and scope of the invention defined in thefollowing claims.

I claim:

In a projectile line charge, a plurality of generally cylindrical solidcharges of explosive, each said charge having a planar face at one endand being rounded at the other end and having a first axial bore and asecond bore of smaller diameter than said first bore and arranged inparallel contiguous relation therewith, said first and secondboresopening through the ends of the respective charges, a continuous lengthof flexible tow rope extending through all of said first bores, saidcharges being secured to and along said rope in equally spaced relationand with said rounded ends arranged to face in the direction of travelof said line charge to prevent fouling, and a continuous length ofPrimacord extending through all of said second bores in succession andlying in snug relation along said rope in each said charge and forming asingle loop between each said charge, said loop having a diameter lessthan the distance between said tow rope and the outer circumference of asaid charge, said Primacord extending at least the length of said linecharge from one end thereof throuh the charge remote from said one end.

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